This is an application to renew support for the Baylor College of Medicine (BCM) Hematology Training Program (HTP) that has been successfully running for 10 years and has trained, or is training, 41 young investigators, 11 of whom are from under-represented minority groups. Of past trainees, 13 are academic faculty performing biomedical research and 16 are still in training. The trainees have published a total of 107 papers directly related to their hematology training. The overall goal of the Hematology Training Program is to foster hematology research by training the most talented young investigators at the pre-doc and post-doc level. Training is provided to researchers in both adult and pediatric hematology who include MD, MD/PhD and PhD trainees, as well as basic researchers performing hematology-related research in diverse departments. The BCM HTP provides its trainees with the mentorship, research skills and experience to ultimately become productive and successful investigators in the field. The program is structured to ensure close mentorship from accomplished senior researchers at Baylor College of Medicine, and to support junior faculty to develop their own mentorship skills. The 33 faculty mentors participating in the HTP have broad teaching and training experience and share a commitment to train young scientists and physician-scientists in hematology research. Their expertise covers a wide range of hematology research areas including stem cell biology, hemoglobin function, iron metabolism, thrombosis, neutrophil function, myeloid cell differentiation, stem cell transplantation and cell and gene therapy. Important components of the BCM HTP are a structured training scheme involving mentored research, a didactic program, and preparation for grant writing. The PI and Co-Directors, Margaret Goodell, David Poplack, and Martha Mims have a history of close productive interaction with each other and a strong record of past trainees, assuring a close interaction and integration of basic research with clinical adult and pediatric hematology programs. Renewal of the Hematology Training Program will ensure continued training of outstanding physician-scientists in hematology at BCM.